Evaluate Attendees |2|
~~~~~~~~~~~~~~~~~~~~~~

The cast and crew of TGS attended a seminar and they were required to
take a test after finishing a series of educational material. The
results of the test are critically important because it will determine
the fate of the show, being a clear indication of how much they care
about the company policies. To determine the results with the highest
possible accuracy, they hire you to create a program that calculates the
results.

Write a function named *evaluate_attendees* which takes two *string*
arguments, namely *answer key* and *responses* files. The *answer key*
file consists of a single line of *uppercase letters between A-E*
separated with a space character. The *responses* file consists of
multiple lines where each line has *attendee name* and *responses*
separated with a space character. Your function should generate the
points of each attendee and return the list of tuples consisting of
attendee’s name as *string* and her/his point as *float* in descending
order with respect to points.

A point of a participant can be calculated as follows: point = correct
answers - wrong answers \* 0.25

*Hint:* You can use built in *sorted*\ () function by using *lambda*
expression.

.. container:: sampleio

   Sample I/O:

.. |2| image:: ../../figures/difficulty_two.png
   :class: difficulty

.. code:: default

   Sample function call:  
       evaluate_attendees("key.txt", "attendees.txt")

   Content of the file "key.txt":  
       A B A B C

   Content of the file "attendees.txt":  
       Jenna A A A A A
       Tracy D E D E A
       Liz A B A B E
       Lutz A B A D D
       Toofer E B A B C
       Frank E E E E E

   Return Value:
       [('Liz',3.75),('Toofer',3.75),('Lutz',2.5),('Jenna',1.25),('Tracy',-1.25),('Frank',-1.25)]

.. raw:: html

   <button type="button" class="collapsible" onclick="toggle()">

Show the Answer

.. raw:: html

   </button>

.. raw:: html

   <div class="hiddenanswer">

.. code:: python

   def evaluate_attendees(key_path, grade_path):
       attendees = []
       
       key_file = open(key_path, "r")
       key = key_file.read().split()
       key_file.close()

       questions = len(key)

       input_file = open(grade_path, 'r')
       for line in input_file.readlines():
           correct = 0
           wrong = 0
           name = line.split()[0]                # seperating name from the rest of the list
           responses = line.split()[1:]          # getting the responses for the exam
           for i in range(questions):            # checking responses one by one to determine result
               if responses[i] == key[i]:
                   correct += 1
               else:
                   wrong += 1
           attendees.append((name, correct - 0.25 * wrong))

       input_file.close()

       attendees_sorted = sorted(attendees, key=lambda item: item[1], reverse=True) # sort the list according to points
       return attendees_sorted

.. raw:: html

   </div>